“I grew up listening to Christmas songs in the 1960s – 'Rudolph the Red-Nosed Reindeer,' Gene Autry, the Lennon Sisters,” he told me during an interview at this year's Virginia Festival of the Book in Charlottesville. “Christmas music was always there, so it was an important family ritual.”

The book looks mostly at holiday songs written since the 1930s, when the first secular, commercial Christmas tunes appeared, written by Tin Pan Alley composers and lyricists and distributed through the still new medium of phonograph recordings. Citing music industry historians, the author places 1934 as the year that saw the launch of the first modern Christmas standards, “Santa Claus Is Coming to Town” and “Winter Wonderland” (the latter of which never mentions Christmas).

Referencing Irving Berlin's “White Christmas,” recorded by Bing Crosby, and Mel Tormé and Robert Wells' “The Christmas Song,” recorded by Nat “King” Cole, Lankford writes that this kind of holiday song, “performed by a well-known singer, pressed on a 78rpm record, and sold on the mass market, would create a new category of popular music.”

Although Americans celebrate several holidays every year, from New Year's Day to Independence Day to Thanksgiving, only Christmas has a wide range of music associated with it.

One reason for that, Lankford surmises, “is that Christmas seems to last longer than most holidays. Every year we have four or five weeks after Thanksgiving” when Christmas is celebrated, not just one day on December 25.

Another reason, he added, is “that it probably just holds a bigger place in our hearts than other holidays. A lot of people that are religious love it for religious reasons and a lot of [people who] aren't involved in religious aspects of Christmas also love it.”

“Mostly what I was looking at was source material in the United States. If you want to understand the songs coming out in the '40s and '50s, you need to see how Christmas was sort of invented in the 19th century by the American middle class. Over and over again we come back to family, home. Dickens was very popular in the United States in the 1840s,” he pointed out, “so I wanted to go back and be grounded in these sources.”

Starting in the late 1940s and continuing through the 1970s, however, novelty songs (“Rudolph the Red-Nosed Reindeer,” for instance) began to push nostalgia to the side, and songs “focusing on the holiday blues and hard times” started to get radio play.

The counterintuitive holiday popularity of mournful songs like “Blue Christmas” and “Pretty Paper,” he told me, really took off in the 1960s, when “everything changes.”

John F. Kennedy was assassinated in November 1963, mere weeks before Christmas, he said.

Then, the next year, The Beatles arrived in America and “music changes quite a bit. Then we start having a variety of revolutions in the street and so the mood of the country changes.”

At the same time, he said, “what we think of as family begins to change. We tend to think of family as being a mother at home, father at work, and two children – or people used to think that [but] that started to change in the Sixties and, I think, it was a little disorienting.”

Many popular singers, even rock stars, record at least one Christmas album during the course of their careers, yet creating a hit holiday song is elusive even for artists normally at the top of the charts.

“It's a really difficult trick to pull,” Lankford explained.

“In one way, most Christmas songs are traditional, so you're going back again to family and home, and so people don't want anything really 'out there.' Weird Al's Christmas songs,” for example, “have not become classics.”

On the other hand, he said, “if you want to be a classic, you need something that people will play year after year, so it has to have something distinctive enough that it's going to stand out from every other song.”

Those, he said, “are the two qualities they would have to have” – simultaneously conservative and distinctive – “to get played five weeks a year and not wear themselves out.”

“I was surprised,” he said, at “how controversial Elvis Presley's Christmas album and [his] Christmas music was in 1957.”

Today, he explained, it seems like Presley is an American icon: “baseball, apple pie, and Elvis.”

Yet in the late 1950s, “when he was touring, he was very controversial and his album was very controversial.”

Lankford recounted a “wonderful story” told to him by a dentist in his hometown of Appomattox.

The dentist's mother was an Elvis fan who "went downtown to buy the Christmas album when it came out. She brought it home, took it out of its sleeve, started to play it, and she didn't get finished with one cut when she said, 'This is the worst thing I have ever heard in my life.' She put it back in its sleeve, took it back to the drug store, and asked for her money back.”

It's easy to see why that controversy of 57 years ago seems puzzling today. This time of year, the tracks on Elvis Presley's Christmas album are played over and over on the radio. Reissued several times, that LP has sold more than 23 million copies and is now considered the best-selling Christmas album in recording industry history.